"Forrest Woodbush is a mysterious Styracosaurus who lives in the wilderness. Like Arlo, he harbors unreasonable fears. His ability to blend into his surroundings helps—along with an unusual (but not-exactly-fierce) collection of forest critters he’s recruited to protect him." He isn't seen again for the rest of the film.
The collection of pets Forrest Woodbush has gathered to protect him is highly eclectic and is composed of several reptiles, mammals, as well as a few birds and butterflies. The pets whose names are known are:
Debbie: a bright red Avisaurus, who seems to be Forrest's favorite. Forrest interprets her singing as advice on what he should do.
Dream-crusher: a large nondescript Didelphodon which protects Forrest from "unrealistic goals."
Destructor: a fox-like Hesperocyon which Forrest believes to protect him from mosquitoes.
Fury: a yellow Hylonomus which supposedly protects Forrest from "the creatures that crawl in the night."